The special tackled an issue that hadn't been talked about since the series came back in 2005: that of the limited amount of regenerations, introduced in The Deadly Assassin. It confirmed that the Doctor had actually used up all twelve of his possible regenerations, before being granted a brand new regeneration cycle at the end of this story. It also served as Peter Capaldi's formal introduction as the new Twelfth Doctor, after making a surprise cameo appearance in The Day of the Doctor.

The special marked the departure of producerMarcus Wilson, finishing his work with the series after Matt Smith's final scene was filmed.

The Doctor is among thousands of ships orbiting a planet after hearing a message being broadcast from it, a three-toned message that no-one can understand. Shrouded in a cape the Doctor visits a ship while holding a Dalek eyestalk to show his bravery, and that he comes in peace. Unfortunately, the ship belongs to Daleks, who fire at him until he teleports back to the TARDIS, where a severed Cyberman head that he calls "Handles" is plugged into the console. Surly after avoiding a near disaster, the Doctor removes his cape and scolds Handles for sending him to a Dalek ship while he was "holding a broken bit of Dalek". Handles, who as a robot interprets everything literally, replies he didn't specify a preference for transport.

The TARDIS phone begins to ring, but the Doctor cannot answer the call from the inside. The ship's telephone device has been incorrectly fed to the dummy handset on the outer shell of the police box. He orders Handles to remind him that he needs to patch it back into the console unit, eventually growing exhausted of Handles's inability to grasp figurative language. He then tells Handles to "Just pick a random number, express that number as a quantity of minutes, and when that time has elapsed, remind me to patch the telephone back through the console unit". Clara is calling the Doctor via the TARDIS phone, and pleads that he pretend to be her boyfriend for her family's Christmas dinner. She is having difficulty squaring things away for the event, including how to cook the turkey properly. At the same time, the Doctor has been put in a bind by having to answer her call from outside the TARDIS doors as he hovers through space among a legion of alien races. He leaves the phone hanging before his companion can clarify that she needs a Christmas date after inventing a boyfriend. The Doctor has identified the arrival of a new ship on the TARDIS scanners, and materialises the TARDIS on board to hopefully greet the occupants in peace. His luck is worse this time: the Doctor accidentally visits a Cybership while holding Handles, where he is also shot at until he returns to the TARDIS again. The Doctor, trying to evade the volleys of laser fire from the Cybermen, and Clara, cooking a Christmas dinner under tension, agree to lend each other some assistance.

Clara caters to three people over for Christmas, her father Dave, her grandmother, and Linda. Clara doesn't let them figure out she's messed up the instructions for cooking the Christmas turkey and runs outside with relief when she hears the TARDIS materalising. The wind catches her paper crown and she lets it be carried away, more concerned that the arrival of her "boyfriend" is just in time to bail her out of a jam.

The Doctor picks up Clara from her home, but gives Clara the strangest greeting yet. Upon entering the TARDIS, she is shocked to see he is naked. She is immediately flustered by his nudity and tells him to stop before he embraces her, daring to ask why he has stripped. He explains by saying he is naked because he plans to go to Church. He uses a holographic filter to project an image of clothes. She takes him inside to meet her family. They appear very embarrassed in meeting him. Dave stares at his behind with a boggled look on his face; Linda is looking on with perplexed discomfort; Clara's gran gives the Doctor a good look over and starts flirting with him - her irreverent giggling suggests she's a bit tipsy. Clara initially does not understand why her friend and family are behaving weirdly, but the Doctor suggests it might be because he didn't update his holographic suit to be visible to her family. She ushers him out of the room with the explanation to her guests that "he's Swedish." Clara asks for an honest opinion of her turkey; The Doctor snarks, "I think a decent vet would give it an even chance." She asks if he has an app for the turkey on his sonic screwdriver. He doesn't like her indignant remark about his screwdriver. The device "doesn't do turkey", nor does anything else. The Doctor tells Clara she would need a time machine. She gives him an indicative glance until he quits missing the obvious solution.

They take the turkey to the TARDIS, where Clara opens up a panel near the floor. She can put the bird in the time winds beneath the console to cook it - or, possibly, bring it back to life, the Doctor points out. Dematerialising the TARDIS, he takes her to the planet's orbit. When asked to identify the origin of the transmission, Handles claims it is Gallifrey, which the Doctor refuses to believe. They are then invited aboard the Papal Mainframe, a space church headed by Mother Superious Tasha Lem. The Doctor gives Clara a pill so that she too will have holographic clothes, as nudity in the Papal Mainframe is considered a mark of respect. Tasha and the Doctor discuss the signal coming from the mysterious planet, while Clara repeatedly sees and forgets several Silents that surround her. She bursts into the room where the Doctor and Tasha are conversing, but forgets why after she does so.

Bald Doctor & The Key in the Quiff Routine - Doctor Who - The Time of the Doctor - BBC

The Doctor and Clara arrive on the planet, and are ambushed by Weeping Angels.

Tasha sends the Doctor and Clara to the planet, but demands that he relinquish the TARDIS key he has snuck in through his holographic clothes, which she is trained to see through. She does not want the Doctor bringing any technology onto the planet, including summoning his TARDIS. The Doctor complies, and Tasha reminds him that she wants both him and Clara back in an hour. Unfortunately, she accidentally places them in the middle of an ambush of Weeping Angels hiding beneath the snowdrifts. Here, Clara is nearly captured by an Angel when it grabs her by the ankle, but the Doctor helps her wriggle lose. The Angels surround them as the heavy snowfall keeps blinding their vision, but the Doctor unzips his coif and pulls out a spare key that lets him summon the TARDIS, which materialises around them. Clara is stunned at the Doctor's hairless head. Once in the TARDIS the Doctor drapes the wig over Handles and reveals that he pulled the "old key in the coif" trick on Tasha Lem. Clara states that she suspects that he just got bored one night and shaved his head, which he somewhat reluctantly confirms. Clara asks if that's what happened to his eyebrows as well. The Doctor replies that they're "just delicate". Clara is bothered by the Doctor's bald head and comments that his prominent ears now stick out like "rocket fins", he is pleased by this comment but does don the wig again.

After they are properly outfitted in winter clothes, they escape to a town called Christmas, a small, quaint community with festive holiday decorations. The Doctor notices that it is 2:00 p.m., but dark outside, so he sums up that the days on the planet must be very short. Meeting a married couple in Christmas, Abramal and Marta, the Doctor and Clara embarrassingly blurt out things they would normally keep to themselves. The couple explains the planet is surrounded by a truth field, so no one can lie, especially around the clock tower. It makes life easier for Marta, but not for Abramal. The Doctor begins to track the origin of the signal to the tower, with a tinge of apprehension to find out what is wrong with such a nice place.

As the Doctor and Clara enter the clock tower, the Doctor has a look of gleeful curiosity, until a particular object slips into the corner of his eye. He turns around and looks at the wall with a bitter stare. Something he has dreaded has returned. Anticipating it, he utters, "There you are. What took you so long?" Clara asks why he is so fascinated by a crack in the wall... Glancing forward, the Doctor has found one last crack in time.

Feeling the seam of this crack, he remembers the many times the cracks have haunted him since he first began life in this incarnation, from the moment he met young Amelia Pond to the crash of the Byzantium, learning that the day the TARDIS exploded would be on 26 June 2010. One more memory of the past reveals what has lurked behind the door of his room on the Minotaur's prison ship. He saw the image of a crack in time on the wall, reflected as a mysterious white glint in his eyes. The Doctor explains his history with the cracks to Clara. He knew he would see the crack in time again, because he felt a personal level of responsibility since it was his TARDIS that blew up the universe. Although the universe had been rebooted, the event had left scar tissue from the damage inflicted, and created a structural weakness in the whole universe.

The Doctor figures out that someone is on the other side of this crack, trying to break into their universe from a separate one through the weakest point. However, it isn't just someone breaking in - it is someone breaking back in. The Doctor asks Handles why he said the message was from Gallifrey. Handles replies that his analysis, according to the TARDIS data banks, matches Gallifreyan origin. Clara is confused, thinking the Doctor told him Gallifrey is gone, but the Doctor reminds her he said it was in another universe. This final crack in time is where the message is being broadcast, and where the truth field is coming from. Suspecting that the Time Lords could be sending the message, both he and Clara exchange anxious looks.

The Doctor takes out a copy of the Seal of the High Council he once took from the Master in the Death Zone. He attaches it to Handles to have him decode the message using an algorithm imprinted in the seal's atomic structure. Handles analyses that the message is a request for information - in other words, a question. Annoyed, the Doctor bickers at Handles for not being frank, but the Cyber-head continues to relay its analysis. The message is being sent through all of space and time on a repeating cycle, which the Doctor deduces is the "oldest question in the universe, hidden in plain sight", as Dorium Maldovar once prophesied to him. Handles issues a warning that the translation will be available to anyone in range of listening. He begins to utter a version of the three tones refined into three constant syllables, which then refines further into the voice of The General. The message is a repeat of the same question: "Doctor who?"

The Doctor realises that this is the Time Lords, trapped in the pocket universe he and his previous selves sent them to, trying to get out. They are issuing a question only he can answer, and set in place a truth field so he must answer without lying. If the Doctor speaks his real name, the Time Lords will know they are in the right place and come through, and all the alien species above will descend on the planet and begin the Time War anew. Horrified, the Doctor figures out the true stakes of the prophecy: he is facing the threat of all hell coming down on his and Clara's heads if the Time Lords come back. He has Clara take a device to the TARDIS and place it in the charger slot for the sonic screwdriver. With half the universe already above the planet, waiting to open fire, he strongly pleads with her to do as he says. Clara returns to the TARDIS and inserts the device in the charger for the sonic screwdriver. The TARDIS goes into autopilot and it returns to Earth, but as soon as she exits the doors, it begins to dematerialise without her. The Doctor has tricked Clara into plugging a device into the TARDIS that transports her home, for her own safety. However, Clara refuses to abandon the Doctor. She sticks her key into the door lock and grabs hold of the TARDIS before it can leave her behind.

The Doctor discovers the truth about the planet.

Tasha contacts the Doctor through a hologram projected in the sky, telling him the return of the Time Lords cannot happen. She is aware this would restart the Time War again, which as a peacekeeper the Church cannot allow. The Doctor refuses to withdraw and let his enemies destroy the planet. He asks her to answer one last question - the name of the planet he's on. She reveals that the planet is Trenzalore – the place where he is supposed to die. Despite his plea that the Time Lords are asking for his help, Tasha will not let him rescue them due to the terrible consequences the Church faces. Unable to reason with her, he chooses to stand his ground on Trenzalore and uses his sonic screwdriver to begin ringing the clock tower bell in vigilance. He summons the whole populace of Christmas to the sound of the bell and declares that he's the new sheriff in town who will defend them. This will be where he has his last stand, to protect his people and the innocent citizens of Christmas from the attackers above, and he is the only one capable of stopping them. The Doctor is about to be sucked into a gargantuan battle that Clara cannot suffer through. Meanwhile, Tasha Lem issues forth an unscheduled faith change to the Church. They will now be dedicated to the solitary cause of bringing silence - the Doctor's silence. He must not be allowed to speak his name before the Time Lords, and war will not begin. She and the congregation exclaim, "Silence will fall!"

For the next three hundred years, the Doctor defends Trenzalore from his enemies. He defends Christmas in a number of ways. One time he disabled the cloaking device on a Sontaran vehicle, allowing the Church to destroy it the instant the vehicle registered on their technology scan. Lacking competence, neither Commander Skarr nor his companion noticed they had been revealed until it was too late. Both were promptly wiped off the planet and received a posthumous apology from ColonelAlbero for their deaths as they were sorted to the appropriate afterlife. Following this victory, the Doctor trapped a Weeping Angel in front of a mirror bearing the message, "With Love from the Doctor", in marker, where it would remain indefinitely quantum-locked by peering at its own reflection. On another occasion, the Doctor tricked a wooden Cyberman, created to be too primitive to set off the alarm, into destroying itself after using both the sonic screwdriver and the truth field to make it think its gun had been turned around. Equipped with a flamethrower instead of laser technology, it blew a gaping hole in its chest. The Doctor told the Cyberman to inform the rest of the Cyberiad that "the Doctor stays" before it ceased functions. Not always fighting, the Doctor found time to have a party with the village in his honour. He held a play and entertained the children of Christmas as the puppet Doctor who fought a Monoid. He even taught them the drunk giraffe dance and how "'cool' was not cool."

According to Tasha, the Doctor seemed to forget of his life before the siege. He spent his spare time fixing the toys the children played with - sometimes a little too much - and grew close to a child called Barnable. He fixed a leak in a barn belonging to Barnable's father, though once again, he went beyond the necessary repairs and turned it dimensionally transcendental, hoping the word won't get out, or else everyone in town might ask him for one of their own. However, the Doctor's lengthy stay on Christmas has distracted him from the life he left behind, which returns when he least expects it. He hears the TARDIS coming back a good three hundred years late, which worries Barnable he may be leaving soon. On the contrary, someone else has arrived, despite the Doctor's efforts to protect her.

The Doctor and Clara are reunited.

Clara returns after gripping to the sides of the TARDIS, which forces the TARDIS to increase the shields and bring her back through the Time Vortex, slowing it down considerably on its journey back to Trenzalore. She meets a Doctor who has spent three centuries defending the town of Christmas. He now has grey hair and wrinkles, and needs a walking stick. The Doctor and Clara at first exchange angry remarks - Clara is strongly upset about being left behind without even a good-bye, and the Doctor becomes irritated that she returned to Trenzalore. However, the two of them can't help but embrace in a warm hug.

The Doctor decides to take Clara to his new home on Trenzalore, the bell tower in Christmas. He has taken residence in the same room with the time crack, now adorned with hundreds of drawings given to him by the children of Christmas. Each drawing shows a child's love for the Doctor and provides a peek back at his bygone adventures, after recounting many stories over the passing centuries to entertain the kids. However, Handles has heavily aged alongside the wearisome Doctor and barely functions. The rusted Cyberman head announces he has developed a fault through his stuttering electronic voice, warning that he doesn't have much time left.

Handles perishes.

Shortly after, Handles dies – but not before finally reminding him that he needs to patch the TARDIS phone back into the console. The Cyberman ceases to function, and the Doctor despairingly shakes his head. Holding back tears, he quietly says, "Thank you, Handles, and well done. Well done, mate."

The sun rises over Trenzalore, and the Doctor informs Clara that he watches the sunrise every day to remind himself of what he is protecting. Though she thinks it is a beautiful sight, Clara is pressed to ask the Doctor why he decided to drop her back on Earth. The Doctor feared that if he had allowed her to stay, he'd outlive her or lose her in battle, and he would have buried her long ago. Clara defiantly tells the Doctor she would have found a way to prevent him from being stuck on Trenzalore, but the Doctor is quick to disagree - "Everyone gets stuck somewhere eventually, Clara. Everything ends."

The Doctor explains he's run out of regenerations.

Clara still isn't convinced it applies to the Doctor, even though he has grown quite old. She says he cannot die, and instead regenerates with a new face each time he is about to perish. The Doctor grimly reveals to her that Time Lords can only regenerate twelve times. She surmises that this shouldn't be a problem, as he is "Number Eleven". He reminds her of "Captain Grumpy", his Time War incarnation; although he didn't call himself "the Doctor", it was still a regeneration. Clara thinks this should be fine, as this now makes him "Number Twelve". He tells her of the regeneration the Tenth Doctor aborted, yet keeping the same face, simplifying the explanation to "I had vanity issues at the time." He is therefore on his thirteenth, and final life.

He and Clara then watch the sun rise for a few minutes, until a thunderous boom from overhead reveals Tasha Lem's holographic face in the sky. She announces to the Doctor that the newly renamed Church of the Silence is requesting parley. The Doctor is being allowed to meet with her to discuss a truce, with his rights and safety sanctified. Tasha offers to have him transported to the Papal Mainframe, but the Doctor declines, knowing he's got his TARDIS back. By the time Tasha deactivates her hologram, the sun has already vanished over the horizons of Trenzalore. The Doctor reminds his companion, "Everything ends, Clara. And sooner than you think."

The Doctor and Clara prepare to board the TARDIS, where they find Barnable guarding it, wondering if the Doctor will leave Christmas. He gives the boy assurance that he's known the Doctor long enough to trust he will return. Barnable promises to wait for him. Clara and the Doctor then arrive back on the Papal Mainframe, now converted into the Church of the Silence, where Tasha still remains in power as a youthful Mother Superious. When Clara mentions her youthfulness, the Doctor simply replies that she is "against" ageing. After centuries of battle with the Church, the Doctor now understands the origin of the Silents. The memory-proof race of aliens are genetically-engineered confessional priests, whom Church members can confess their sins to, then later forget.

When the Doctor returns to Tasha's chapel, he discusses the parley at a table instead of a bed (as seen when he first arrived at the Papal Mainframe). Tasha explains a renegade faction of the priests belonging to a sect of the Church called the Kovarian Chapter broke away and travelled back in time to stop the Doctor from reaching Trenzalore. However, Tasha has been helpless against the onslaught of the Doctor's enemies since his long battle began. The Mainframe itself was attacked by the Daleks three days prior to their meeting. The Doctor asks why she didn't call for help. Tasha replies, "I tried. I died in this room, screaming your name. Oh... I died. It's funny the things that slip your mind..."

With those words, the horrified Doctor realises that Tasha and her crew have been killed by the Daleks and turned into Dalek puppets. Eyestalks burst out from their skulls - even the Silents. This is a trap set by the Daleks to snare their greatest enemy.

The Daleks, having conquered the Church, confront the Doctor with their memories restored.

As Tasha succumbs to the puppet conversion, three Daleks enter the chapel and accost the Doctor. He is surprised that they now remember who he is, after Oswin Oswald purged the Dalek Pathweb of their information about him. The Daleks reveal that their memories of the Doctor resurfaced after they harvested replacement information from Tasha Lem's cadaver. Because of this, the Daleks have redoubled their efforts to stop him from saving Gallifrey, well aware their nemesis race, the Time Lords, could return to wipe them out.

The Doctor prepares to surrender, allowing the Daleks to think he would let Clara be exterminated. Clara plays along with the bluff, realising the Daleks would kill her even if he tried to save her rather than betray. The Doctor then praises Clara for being a strong-willed woman, but also berates Tasha, claiming her Church was useless and she was too spineless to be of any help to him in the war. The insults urge Tasha to regain her mind, subconsciously furious at the Doctor, giving him a fierce slap. She then uses her puppet form's gunstick to wipe out the Daleks. The Doctor kisses her and apologises for having to make her angry, encouraging Tasha to keep fighting the Dalek programming still inside her. As he and Clara escape to the TARDIS with Tasha's help, Tasha protests that she has kept fighting for the sake of the peace, not the Doctor and his ego.

Inside the TARDIS, a timer bell dings, alerting the Doctor that Clara's turkey has finished cooking - or woken up. Before Clara goes to check on it, she asks the Doctor to promise her he will never leave her behind again. He complies. As she goes down to the lower level, the Doctor sees Barnable still beside his TARDIS. The Doctor quietly replaces the charger inside the TARDIS and returns to Christmas town. While Clara thinks he has stepped out, she exits the TARDIS with turkey in hand only to find that she is back on Earth. He has tricked her into leaving his company for the second time, and the TARDIS soon makes a return flight to Trenzalore right after she exits it with her cooked turkey. This time, she really is stranded, without any means of return.

On Trenzalore, Barnable questions why the Doctor has brought back his TARDIS if he doesn't intend to leave the planet. He explains it is a reminder that he might leave someday.

The Doctor continues his long war against his enemies, as a great many years pass. Now on good terms with the Church again, he is able to ally with their soldiers and the Silents instead of facing them as villains. Together they defend the planet from attackers above, until only the Daleks are left. The troops of the Church help the Doctor defend Christmas against aerial attacks by fighter pods and land assaults from Dalek tanks. Countless casualties mount up, but the Doctor maintains his stand on Trenzalore as time wears on.

Clara back at home with her family.

Meanwhile, having returned to her family (who assume she's broken up with her "boyfriend"), Clara asks her grandmother about her late husband, who consoles her with memories of him. Clara cries when she notices how similar they sound to her own memories of being with the Doctor. She then hears the TARDIS engines and joyfully runs outside, thinking the Doctor has changed his mind. Instead, she finds the TARDIS piloted by Tasha, claiming, "Flying the TARDIS is easy... it's flying the Doctor that's hard." She returns Clara to Trenzalore to see the Doctor one last time, saying she could not let him die alone.

A very old and dying Doctor is amazed to see Clara again.

Clara reenters the Doctor's old sanctuary in the bell tower to find an elderly man toiling away at fixing a child's wooden horse. After announcing her presence to him, he turns around to reveal a heavily wrinkled face with long, balding white hair, glasses perched on his nose to help his weakening eyes. The Doctor is now very old and often acts slow and slightly confused. Clara gives the Doctor a cracker from her family's Christmas festivities and helps the ailing Doctor to open it. She recites the poem inside with the hope it may cheer him up:

From above, a huge Dalek mothership and several Dalek fighter pods surround the clock tower. A booming Dalek voice from the mothership demands for the Doctor to show himself. Suffering memory issues, he mistakes a young man for Barnable who comes into his tower dwelling to warn him of the Daleks' arrival. Sadly, Barnable is long gone and the Doctor can't recognise that fact, and buys him off with the notion he has a plan. Unfortunately, the senescent Doctor has no more plans left after 900 years on Trenzalore. At the very brink of his final incarnation's death from natural causes, he still won't release the Time Lords, knowing that it would mean hell for all the universe. All his enemies have withdrawn save for the Daleks, whom he has been fighting with the aid of the Silence. The Daleks have chosen to remain in battle with the Doctor, because unlike the other alien races who have opposed the return of the Time Lords, they have a very personal stake in the siege. The Doctor is threatening to unleash their nemesis species from the crack in time. After experiencing the fury of the warring Time Lords once, the Daleks will see this battle through to the end if it means preventing another Time War with their greatest enemies.

The Daleks launch their final attack and the Doctor, finally out of ideas, weapons, and regenerations, goes to meet them. The Doctor is committed to dying, thinking this is the way things are fated. Clara refuses to let him do this, but the Doctor believes death is unavoidable now that the Time Lords are removed from the universe and cannot change the course of events. He asks Clara to promise she will stay hidden and safe, calling it "one last victory". Intending to impart a final farewell on Clara, he wipes her tears as he says, "Allow me that. Give me that, my impossible girl. Thank you. And goodbye." In his worn out clothes, the Doctor slowly totters up the bell tower with his walking stick to face his extermination, expecting it to be a while before his death since the Daleks "take so long to say anything".04:06

Eleven's Hour is Over - Clara Begs for Help - Doctor Who - The Time of the Doctor - BBC

"Help him." Clara pleads to the Time Lords.

After he leaves, a distraught Clara returns to the crack in time. She has not given up hope on the Doctor's survival. Clara begins pleading with the Time Lords to save the Doctor, saying: "You've been asking a question, and it's time someone told you you've been getting it wrong. His name is the Doctor! All the name he needs, everything you need to know about him, and if you love him - and you should - help him!" Receiving no response, she turns away. Behind her, the crack abruptly closes.

Running outside to see what is happening, Clara sees the Doctor, at the top of Christmas's clock tower, preparing to die. He admits defeat to the Daleks, and jests that they've been trying to kill him for so long that he's actually dying of old age. The Dalek voice from the mothership announces with certainty, "You will die, and the Time Lords will never return." Despite these words, the Doctor has not been shot down where he stands. Rightfully so, the Daleks lack the courage to finish him off, thinking he might have some trick up his sleeve, until the Doctor explicitly states he has nothing left to stop them this time. The Daleks begin opening fire on the town below, but still desist from attacking him directly.

As the Daleks begin their attack, however, a new, much larger crack appears in the night sky, apparently unnoticed by all but the Doctor. Golden energy emanates out of it and enters the Doctor's mouth. As he swallows the crack's gift, the Doctor's eyes widen in surprise as he realises what has just happened, and his mood completely turns over when he sees his hands glowing with the all-too familiar force that has saved him from death twelve times before; the Time Lords have granted him a new cycle of regenerations.

Unaware of this, the Daleks begin to taunt him, asserting that: "The rules of regeneration are known! You have expended all your lives!" However, repossessed of his old vigour, the Doctor begins to dance around and act like his old self again. He twirls his walking stick and defies his enemies with the mocking challenge "Sorry? What did you say? Did you mention the rules?" before giving them a little advice: "Tell me the truth if you think you know it; lay down the law if you're feeling brave. But, Daleks - Never. Ever. Tell Me THE RULES!". He begins boasting that his unprecedented thirteenth regeneration is "breaking some serious science" and is "gonna be a whopper!"

"Love from Gallifrey, boys!" The Doctor regenerates for the thirteenth time, destroying the Daleks.

As his impossible regeneration begins, Christmas town's clock strikes twelve. The Daleks begin to panic as they realise he really is regenerating, as the Doctor challenges his enemies to kill him, telling them: "If you want my life - Come. And. GET IT!" He whips his arms around and channels his regeneration energy skyward to destroy the Daleks and their ship. Several Dalek fighter pods are blown right out of the sky as Clara rushes out to tell the people of Christmas to hurry and take shelter from the chaos about to begin. All of the citizens rush into the tower as destroyed and burning fragments of Dalek fighter pods and their pilots rain down on the townscape. With a final, devastating blast to the Dalek mothership, the Doctor lets out a triumphant roar of: "Love from Gallifrey, boys!" before directing all of the energy he has left through his hands and head. His finishing assault climbs very far into the air and wreaks havoc on the gunship, eliminating it from the skyline. An enormous explosion results from his regenerative energy, obliterating every single Dalek attacking the planet as the shockwave blows them to smithereens. The ground quakes, embankments of snow rumble loose in cascading avalanches, and the top of the clock tower is blown apart. The force of the explosion is so powerful, it even rocks the TARDIS.

In the aftermath of the Doctor's regenerative backdraft, the shaken villagers of Christmas emerge from hiding. A woman sobs from the impact of what has happened while others work quickly to clean up the scene of bedlam and rescue others needing help. Clara quickly returns to the TARDIS in search of the Doctor, finding the call box door open, where the outside phone mysteriously lies off the hook; she puts it back where it should rest and goes inside.

"Times change...and so must I." The Doctor's new regeneration begins.

She sees the Doctor's worn out winter clothes splayed on the TARDIS console floor, while a nearly-empty bowl of fish fingers and custard sits on the control panel. She hears footsteps coming up the stairs. She turns to see the Doctor, with his current incarnation's youth restored and dressed in his normal clothes. Clara's joy at seeing a "young" Doctor quickly fades when he informs her that this is "just the reset" - the process of change has started, and cannot be stopped. He enjoys one last taste of the fish custard, a meal he relished at the very start of his now fading incarnation. Clara is saddened greatly when she realises that the Doctor she knew is about to disappear.

However, the Doctor is not upset about the regeneration yet to come. He understands how fast everything about him and life itself can be gone in a moment, because it is always changing. He comforts Clara by telling her that times change, and so must he. The Doctor's hand begins to glow with regenerative energy and he smiles.

"Raggedy Man... good night."

Suddenly, he sees a little girl running through the balcony of the TARDIS with cheerful giggling, with every inch of its walls covered in her drawings of their adventures together, alongside those given to him by the children on Trenzalore. Aloud, he calls out to Amelia. Confused, Clara asks who Amelia is, and he describes her as "the first face this face saw." Happily awaiting the regeneration, the Doctor gives this incarnation a fond eulogy. He assures Clara, "We all change, when you think about it, we are all different people, all through our lives, and that's okay, that's good! You've gotta keep moving, as long as you remember all the people that you used to be. I will not forget one line of this, not one day, I swear. I will always remember when the Doctor was me." He then sees an adult Amy Pond in the TARDIS. Amy descends from the balcony, places her hand against his cheek, and tells him, "Raggedy Man... good night."

The Doctor places his hand against her face as well, only to see he's reaching out for air; his vision of Amy and the drawing-covered TARDIS wall was a hallucination. Ready to move on and become a new man, the Eleventh Doctor removes his cherished bow-tie, dropping it to the floor, before seemingly focusing on his impending regeneration. In tears, Clara begs him not to change and reaches out to him. Extending his hand - now glowing with regenerative energy - towards her, he smiles wearily and whispers "Hey...", and then suddenly jerks his head back...

In nearly an instant, accompanied by a sudden flash of golden light and an explosive sound, the Doctor completely changes from the youthful, geeky alien Clara knew, to a tall, gaunt, older-looking man with short silver hair and the impeccable razor-sharp gaze of the mysterious Doctor from the future that joined the previous twelve to rescue Gallifrey from the Time War. Utterly dumbfounded by this new face, Clara can only watch open-mouthed as the Twelfth Doctor stares her right in the eyes, before stumbling backwards with a grunt of pain, clutching his abdomen. He proclaims, "KIDNEYS! I've got new kidneys! I don't like the colour..." Bewildered, Clara can only ask if it's the colour of his kidneys he doesn't like. Suddenly, the TARDIS begins shaking. The new Doctor not only tells her that they're likely to be crashing into something, but to her horror, he says he has "just one question...do you happen to know how to fly this thing?"

Not every person who worked on this adventure was credited. The absence of a credit for a position doesn't necessarily mean the job wasn't required. The information above is based solely on observations of the actual end credits of the episodes as broadcast, and does not relay information from IMDB or other sources.

The Doctor refers to his Time War incarnation as "Captain Grumpy". He also says that he had a "vanity problem" as the Tenth Doctor, referring to his regeneration from that body into the same one.

The Doctor claims he is obsessive-compulsive.

The Doctor has shaved his hair, making use of a wig to hide a TARDIS key inside its coif while presenting Tasha Lem with a decoy key. Apparently, this plan was not devised deliberately, but after the Doctor got bored and found a razor. Clara asks him if he had sheared off his eyebrows as well, but the Doctor defends them as being "delicate".

Clara notices the Doctor's ears stick out much more without any hair and compares them to rocket fins; the Doctor takes it as an uplifting compliment.

When the Doctor suggests potential aliases to use while on Christmas, Clara jokingly suggests "Daisy".

The Doctor explains that he has exhausted his regeneration cycle due to the War Doctor and the regeneration the Tenth Doctor aborted by channelling the energy into his severed hand. He is granted a new cycle by the Time Lords before he can die for a thirteenth and final time.

Clara has been using the TARDIS to meet deadlines such as birthdays and restaurant bookings. The Doctor also begs her learn how to use iPlayer, indicating that she also uses the time machine to catch up on missed programmes.

The Sontarans have invisibility shields to mask their presence in Christmas town from the Papal Mainframe. This does not bode well for a bumbling Sontaran duo who cannot see if the shields are up, getting them both obliterated by the Papal Mainframe when the Doctor deactivates the cloaking device with his sonic screwdriver.

The Doctor and Clara make use of holographic clothes.

In Christmas, a Truth Field is in force. The Doctor already knows about such fields, but hasn't encountered one for ages.

The Cybermen engineer a special wooden version of their kind to sneak into Christmas without alerting the Papal Mainframe's technology detectors. It uses a flamethrower as a weapon and chants, "Incinerate" rather than "Delete" or "Upgrade in progress".

This is the first televised regeneration story in which the Doctor regenerates at the end of the story to end on a shot of a character other than the Doctor and the second since The War Games not to end on the Doctor's new incarnation. In this case, this story's final shot shows Clara's reaction to the newly regenerated Twelfth Doctor, rather than the Twelfth Doctor himself.

This story takes place over a longer amount of time than any other, with the Doctor having lived through 900 years by the end of the episode.

Starting its broadcast at 19:30, this episode has the latest transmission time of a Doctor Who Christmas special.

This is the shortest regeneration story (in overall run time) to be broadcast on BBC1, as The Night of the Doctor was only shown on Red Button.

The regeneration is presented differently from other regenerations shown in the revived series, with the use of a prolonged explosion of energy occurring before the actor transitions. The final transition consists of a brief flash of golden light around the actor's head.

Regenerations in the revived series are presented as getting bigger and stronger each time. The Ninth Doctor's regeneration into the Tenth Doctor's introduced the regeneration flames. The Tenth Doctor's regeneration into the Eleventh Doctor's used the same effect but as a result of holding it in for too long, causes damage to the TARDIS. When the Eleventh Doctor's regenerative abilities are reset for the beginning of a new cycle, the effect is big enough to destroy an entire Dalek mother ship and several fighter pods. However, when the first regeneration after the reset completes itself (the physical change from Eleventh to Twelfth), it is shown as a (relatively) simple transition.

This episode reuses incidental music from TV: The End of Time, another regeneration story. When the Siege of Trenzalore begins, "Final Days" starts playing. As Clara approaches the building where the elderly Doctor waits, the piece "Four Knocks" can be heard. The piece had been used in the previous regeneration story as the Tenth Doctor rages about his impending death to a trapped Wilfred Mott, which preempts his eventual regeneration.

Before filming for this special began in September 2013, Matt Smith agreed to play a role in the divisive American film, Lost River, originally known as How to Catch a Monster. His character was depicted as having a thug-like buzz cut, which meant Smith had to have his signature quiff completely shorn off. By the time the filming was underway for the special, Matt's hair had not grown back enough to fill out the Eleventh Doctor's hairstyle. It was decided that he would use a hairpiece identical to his quiff, which also made it easier for makeup artists to apply ageing effects through older-looking hairpieces. In a humorous moment in the episode that references the wig, the Doctor, surprising Clara, removes a wig to reveal he is bald. (A latex cap was used to achieve the effect)

Coincidentally, Karen Gillan had had her own head shaved at the time, as part of her role in the film Guardians of the Galaxy. She can be seen wearing a wig made out of her own hair for her brief appearance in the special, meaning both Matt and Karen are humorously in wigs.[2]

During the filming of the special, Matt Smith suffered an injury to his leg and later had to visit a physical therapist to recuperate from the accident. This injury inspired a rumour that the script for the special would be altered to have the Eleventh Doctor lose a leg when the Weeping Angels attacked. The rumour appeared to have been proven false when no such event took place in the episode, though Smith is seen using a cane in a number of scenes and his mobility prior to his regeneration is noticeably limited; in both cases these factors were worked into the storyline. However, in the later short story collection, Tales of Trenzalore: The Eleventh Doctor's Last Stand, it is revealed that the Doctor did in fact lose a leg and was equipped with a wooden leg during the later stages of this story, although on screen the regeneration sequence does not directly indicate the regrowth of a leg. Also, even after he starts using a walking stick, the Doctor is shown to have full use of both his legs.

With their role in The Day of the Doctor, this marks the second time the Daleks have featured in two consecutive stories, excluding separate parts of multi-part stories, and cameos (such as flashbacks). The first time was Frontier in Space and Planet of the Daleks. However, Planet is a continuation of Frontier and both deal with parts of the same Dalek threat, whereas some time has elapsed between the events of Day and Time and they both involve two separate Dalek threats: the Time War and the New Dalek Paradigm respectively.

Though considering himself not much of a "weepy guy", during the table read-through for the script of The Time of the Doctor, Matt Smith had an emotional breakdown while trying to read his final lines - specifically "I will always remember when the Doctor was me" - and cried. Steven Moffat immediately came over to his seat to comfort him while Jenna Coleman tried to avoid being overcome with sadness herself. [source needed]

The music that plays out Matt Smith's regeneration scene is a Series 7 music track composed by Murray Gold, "Infinite Potential", which is a solemn version of "The Long Song" heard in The Rings of Akhaten. It is followed by a sampling of the Series 6 track "My Silence" as he removes his bow-tie.

The Doctor being given a new regeneration cycle in this story narratively sets up the potential long-term continuation of the character well beyond the previously-set limit of twelve regenerations.

This story was promoted as the 800th episode of Doctor Who. In terms of individual instalments, the actual total is higher, but a poster included with DWM 468 specifies that this total does not include minisodes or prequels.

Because Caitlin Blackwood, who had played young Amelia Pond in previous episodes, had aged into a teenager by the time of the episode's filming and the Doctor's hallucination was of the young Amelia as she had appeared in The Eleventh Hour, young Amelia was played by an unknown child actress. To disguise the fact that it was a different actress, young Amelia's face is obscured by drawings as she runs around.

The poem the Doctor receives from Clara's Christmas cracker states "Eleven's hour is over now; the clock is striking Twelve's" which references the Eleventh Doctor's first full story, TV: The Eleventh Hour.

This is the first Christmas Special to feature the same main cast as the previous one.

This is also the first time a Christmas Special credits all of/only the same people as the other episodes broadcast in that year.

This is the last story to feature the title sequence that debuted in TV: The Snowmen.

Before she enters the TARDIS after the siege has ended, Clara finds the external phone off its hook. The reason for this was explained in the subsequent episode as an exhausted Eleventh Doctor, shortly before his regeneration, calls Clara in her near-future imploring her to help the Twelfth Doctor adjust to his new persona. Smith filmed the scene during production of this story, though the other end of the conversation wouldn't be filmed for another 5 months.

The Twelfth Doctor mentions having new kidneys. In Let's Kill Hitler, the Eleven Doctor's kidneys were the first thing to give out on him when poisoned with the Judas tree lipstick River Song used.

According to an interview with Peter Capaldi and Jenna Coleman, Capaldi's first lines as the Doctor were improvised; Coleman even described his outburst of "Kidneys!" as singing.

This is the second consecutive regeneration story to include the word "Time" in the title, following The End of Time.

Because of the leg injury suffered by Matt Smith during filming, the Doctor would lose a leg during the episode. This is both true and false. The middle-aged and elderly versions of the Doctor both rely on a walking stick to get around. It was later confirmed that a line of dialogue cut from the episode did reveal that at some point the Doctor lost a leg, and the circumstances surrounding this were explained in the tie-in anthology Tales of Trenzalore: The Eleventh Doctor's Last Stand, however no reference to this is made on screen. The fact Smith was injured is true and he can be seen hobbling around on the TARDIS prior to the regeneration.

On 20th December, the Daily Star tabloid published the spoiler that a "fan favourite" character would appear in the episode during the regeneration. This led to several days of speculation as to who it might be before it was revealed that Amy Pond was the returning character.

Jenna Coleman would have a nude scene. She remained fully clothed from the perspective of the audience. Matt Smith was seen in the nude, the camera angle placing the TARDIS console in the way of a higher content rating.

While the Doctor is waiting for Handles to confirm the planet's name, he turns his back to the camera and his coat collar is turned up. The shots before and after the collar is turned down.

When the Doctor and Clara arrive at the Papal Mainframe, the right column of the TARDIS is noticeably missing.

During the wide shot of the Doctor teleporting onto the Dalek ship, he lowers his hood and raises the Dalek eyestalk above his head. He repeats both actions in the next shot.

When the TARDIS lands on Trenzalore silently, the telephone panel sign is gone.

There also seems to be a video error when the TARDIS has landed. When the Doctor and Clara walk out of the TARDIS, faded images of the lighted parts (Windows, police box sign and lamp) appear above the prop.

The Doctor's hairstyle changes between Amy's hallucinatory farewell and the Doctor shown reaching out into thin air.

When the Doctor tell the Daleks "Never, ever, tell me the rules!" He is holding his walking stick in his left hand. However, when he exclaims "Oh, look at this. Regeneration number 13!" the stick is in his right hand.

After his regeneration, the Twelfth Doctor's first line is "Kidneys! I've got new kidneys! I don't like the colour...". He stumbles back against the TARDIS console as he cries out "Kidneys! I've got new kidneys!". In the next shot, however, as he says "I don't like the colour...", he is standing to the left of the console (as seen by the viewer).

When the Doctor projects his hologram clothes onto Clara, Clara comes through the door and turns right. Then, when the Doctor flicks switches, those switches are on the other side of the console.

At the very end of the shot of the Doctor laughing before destroying the Dalek saucer, he turns his head towards the left of the screen. However, in the next shot, when he shouts "Love from Gallifrey, boys!", his head is turned to the other side of the screen.

When the Doctor and Clara are in the TARDIS after the Weeping Angel scene, the Doctor dematerialises the TARDIS, and puts the lever in the up position. In the next shot, when the Doctor says 'The Mysterious Message' it is in the down position. Later, it's back in the up position again.

When Clara exits the TARDIS with the turkey the back of the police box prop is clearly visible.

The Doctor explains the cracks in time and the events of the reboot of the universe to Clara. (TV: The Big Bang)

To allow translation of the message, the Doctor uses a Seal of the High Council of Gallifrey, claiming he "nicked it off the Master in the Death Zone." The Third Doctor, while there, did exactly that, incorrectly assuming that the Master had himself stolen it. The Doctor stated at that time he would return it to the High Council at the "first opportunity". Clearly he never got around to it. (TV: The Five Doctors)

The Doctor confirms to Clara that although he is "Number Eleven", he has in fact used all twelve of his regenerations, and is therefore unable to regenerate again. The two "missing" lives are the War Doctor (who was not generally referred to as "the Doctor" due to his actions in the Time War, and the fact that he rejected the title moments after his regeneration by declaring "Doctor, no more."), (TV: The Day of the Doctor) and the abortive regeneration by the Tenth Doctor when he sent his regenerative energy into a matching bio-receptacle (his severed hand) rather than change. (TV: Journey's End) The Doctor's statement also implies that River Song's sacrifice of her remaining regenerations to save his life only transferred the healing effect of regenerative energy, not her remaining lives. (TV: Let's Kill Hitler)

It is again confirmed that Time Lords can only regenerate twelve times, for a total of thirteen lives, (TV: The Deadly Assassin, et al.) but that a Time Lord can be granted a new regeneration cycle. The Master had been offered a new regeneration cycle by the High Council to persuade him to rescue the various Doctors trapped in the Death Zone, (TV: The Five Doctors) and was apparently given one when he was resurrected to fight in the Time War. (TV: The Sound of Drums)

Regenerative energy again proves to be highly damaging to non-organic objects, with the Doctor using the regenerative reset he undergoes prior to his full regeneration to destroy the Daleks attacking Trenzalore. When the Tenth Doctor regenerated, some of that energy hit the TARDIS console, causing major damage and sending it out of control. (TV: The End of Time)

The Doctor visibly ages during the 300 years between when he sends Clara home and when she returns, gaining grey hair and wrinkles and requiring a cane to walk. He ages even further during the 600 years between when he sends Clara home again and when Tasha Lem collects her to say goodbye to him. Previously, the Doctor spent 200 years running from his fate at Lake Silencio, yet was apparently young enough in his body then to not appear to age much. (PROSE: Tales of Trenzalore: The Eleventh Doctor's Last Stand, TV: The Impossible Astronaut)

Like the Tenth Doctor, whose visible injuries were healed as the regeneration process began, the Eleventh Doctor undergoes a pre-regenerative "reset" to his original youthful self. (TV: The End of Time) This is the first time the Doctor has been explicitly seen to "de-age" prior to undergoing full regeneration; his comments about the reset indicates this to be uncommon. A possibly similar (but never-explained) apparition, the Watcher, was seen by both the Fourth and Fifth Doctors prior to their respective regenerations (with the former meeting a physical manifestation and the latter encountering a mental recreation within his own mindscape). (TV: Logopolis, AUDIO: Winter)

It is learned that Madame Kovarian led a rogue faction of the "Church of the Silence" that broke off and travelled back along the Doctor's timeline, trying to stop him from reaching Trenzalore and answering the First Question. Their actions failed, and in fact caused the events they feared to occur - trying to blow the TARDIS up (TV: The Pandorica Opens) caused the cracks to appear, and the assassin they manufactured to kill the Doctor - River Song - (TV: A Good Man Goes to War, Let's Kill Hitler) ended up being the Doctor's wife and ally. (TV: The Wedding of River Song) The Doctor called this the Destiny Trap - "You can't change history if you're already a part of it."

A similar series of events transpired when guerrillas travelled back in time to the 20th century to assassinate Styles, in the belief his death would prevent the Dalek invasion of Earth in the 22nd century. Their doing so actually led directly to it. (TV: Day of the Daleks)

The Silents are revealed to be high ranking Confessional Priests of the Papal Mainframe (later the Church of the Silence), which were genetically engineered to allow people to confess their sins without remembering doing so, accomplished by fashioning the priests so anyone looking at them would forget their encounter when they looked away.

Dalek puppets are used. (TV: Asylum of the Daleks) Tasha Lem is able to resist her conditioning and fire on three Daleks in a way that mirrors Jenibeth Blakely, and seemingly resists being taken over again for centuries - a Dalek puppet would not be allowed to take the TARDIS to collect a companion to be with the Doctor. (PROSE: The Dalek Generation)

This is not the first time someone rode through the Time Vortex on the outside of the TARDIS. This was previously done by Captain Jack Harkness (TV: Utopia) and the Doctor himself (TV: Hide). Both the Doctor and Clara survive the trip due to the TARDIS shielding them; Jack, who traumatised the TARDIS due to his unnatural immortality and ability to resurrect, was not shielded and, therefore, "died" (again).

The town of Christmas has a small graveyard with headstones identical to those in the mass grave from Trenzalore's alternate future. (TV: The Name of the Doctor)

At his oldest before the regenerative process, the Doctor's hairstyle resembles that of his first incarnation. (TV: An Unearthly Child, et al.) He also carries a walking stick like his earliest incarnation sometimes did. (TV: Marco Polo, et al.)

This Doctor still has a powerful dislike for wine, shown when he immediately spits out his wine back into its glass after sampling the drink that Tasha Lem courteously offers him, though what precisely the drink actually is never confirmed. (TV: The Lodger, The Impossible Astronaut) In contrast, the Third Doctor was fond of a good-quality drop. (TV: Day of the Daleks)

The Doctor fixes a little girl's broken toy train while staying at Christmas, but goes too far and bends to his desire to add modifications, such as anti-gravity flight mechanisms. He previously overhauled the Digby Estate with various unnecessary contraptions to impress Madge Arwell's children. (TV: The Doctor, the Widow and the Wardrobe) His previous incarnation made a DNA detector that was supposed to go "ding!" in the presence of a Zygon, but didn't know when to stop himself, giving it the ability to microwave frozen dinners from up to twenty feet and download comics from the future. Even worse, it proved unreliable in Zygon-detecting. (TV: The Day of the Doctor)

The Doctor forgetting how to fly the TARDIS isn't the first time the Doctor has had a memory-related mishap after regenerating. Most of his incarnations have experienced some small, short-term memory loss and/or personality confusion immediately following their regenerations (presumably due to the physical trauma of complete cellular rejuvenation). The Eighth Doctor in particular forgot who he was until the Eye of Harmony was opened. (TV: Doctor Who)

Similar to how the Doctor kept Handles, a non-sentient robot, alongside him as company on Trenzalore for 300 years, an alternate version of Amy Pond who had grown 36 years older when she became trapped in the Two Streams Facility converted a non-sentient Handbot into the likeness of her husband to keep her company. (TV: The Girl Who Waited)

This is not the first time the Doctor has spent multiple centuries living on one planet at a time. As the Eighth Doctor, he remained on Orbis for 600 years. Similarly, he became quite forgetful with age. (AUDIO: Orbis)

Clara discovers the TARDIS telephone has been left off the hook for some unknown reason. It turns out that after defeating the Daleks, having his physical appearance reset to his more youthful form and on the verge of regenerating, the Eleventh Doctor had taken the exterior phone into the TARDIS. He then called Clara's mobile in the near future to help her deal with his regeneration. (TV: Deep Breath). By the time Clara joins him in the TARDIS, the Eleventh Doctor seems content to finally regenerate into his next incarnation.

A bundle including the Christmas Specials mentioned above was released on Google Play, iTunes and Amazon Instant Video in HD or SD. It included the Farewell to Matt Smith featurette. The Amazon Instant Video release also added Prequel to the Doctor, the Widow and the Wardrobe, Vastra Investigatesand The Great Detective.

The special was added to Netflix instant streaming in the US during September 2014. It is listed as episode 16 of Series 7. It is also available on Hulu.

Contrary to common belief, season 10 kicked off in the last week of December 1972 — not in 1973, as would be expected. Season 10 actually began nine years after season 1 started. In fact, The Three Doctors began nine years to the week after The Daleks first aired.

For the purposes of this list, "Series 4" is considered to be the production series 4, which ran all the way from Time Crash to The End of Time.

The years seen in this section may seem decidedly "off". Remember, however, that this list only gives the first year in which an episode from a series was broadcast. David Tennant, unusual amongst other Doctors, began and ended on special episodes, not regular ones. Thus, his series actually begin in 2005, 2006 and 2007 — not 2006, 2007 and 2008 as is commonly thought.

For the purposes of this list, a "regeneration story" is one in which a regeneration is actually and initially depicted. For this reason The War Games is not included below, even though it is commonly thought of as a "regeneration story". It doesn't actually include a clear scene of regeneration, and the preponderance of stories in other media confirm that the Second Doctor did not regenerate at the end of it. Additionally, immediate post-regeneration stories, like the 2005 Children in Need Special — and ones like Castrovalva, where the regeneration sequence was replayed — are not included.

Regeneration is usually considered a biologic process exclusive to Time Lords and a few other species. However, some consider Regeneration and The Eclipse of the Korven to also be "regeneration stories", though neither describes anything close to a biological process. Korven is a particularly hard one to include in this list, because K9 is said to "regenerate" but is largely physically unchanged.

Because of the ubiquity of this race, no attempt will be made here to list every appearance in every medium. Instead, we focus on televised appearances here, and invite you to explore a complete list of appearances elsewhere.